Keeping in mind that the yin energies of the Heart beget your insights and the yang energies provide your expression of them, a person with Heart Yin Deficiency will be rigid and inhibited, unreceptive to new ideas, with common symptoms of set jaw, tight neck and back, and reduced respiration. A person with Heart Yin Excess is likely to be easily agitated and fatigued due to heightened receptivity to the inner chaotic world of the unconscious and constant sensory and emotional impingements from the outer world . . .
— Gail Godwin, Heart